Recording apparatus

ABSTRACT

A recording apparatus having a black ink recording head for discharging black ink onto a recording material and at least one single color non-black recording head for discharging non-black ink onto the recording material includes a recording head driver for driving the recording heads to discharge the ink onto the recording material; and a controller for controlling the recording head driver so that a volume, per unit area of the recording material, of the black ink discharged from the blue ink recording head and deposited on the recording region of the recording material is larger than that of the non-black ink discharged from the non-black ink recording head and deposited on the recording region of the recording material.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a division of U.S. Pat. Appln. Ser. No. 08/375,174,filed on Jan. 18, 1995 now U.S. Pat. No. 6,102,520, which was acontinuation of Appln. Ser. No. 08/048,198, filed on May 3, 1993, whichwas a continuation of Appln. Ser. No. 07/685,210, filed on Apr. 15,1991.

FIELD OF THE INVENTION AND RELATED ART

The present invention relates to a recording apparatus usable withoffice equipment or communication equipment such as a copying machine, afacsimile machine, a word processor, a personal computer or an officecomputer, more particularly to an ink jet recording apparatus whereinink is discharged or ejected through an outlet to a recording medium toeffect the recording.

In a color ink jet recording apparatus, one dot is printed for amonochromatic (yellow, magenta, cyan or black) picture element, whereastwo dots are printed for a picture element in the case of mixed colorssuch as red, green or blue. A color image is formed on a recordingmaterial by the mixture of a single color dot print and a mixed colordots print.

In a conventional color ink jet recording apparatus, particular coatedsheet is used as the recording material. As long as the particularcoated sheet is used, the droplet of the color ink is such as to meetthe spread of the ink on the particular sheet, and therefore, the ink isproperly absorbed and fixed without any problem. This is because withthe particular coated sheet, the degree of the spread is determined soas to meet the droplet discharged from the recording apparatus.

However, requiring the user to always use the particular coated sheet ina color ink jet recording apparatus, is not desirable because the coatedsheet is more expensive than plain paper, because the coated sheet ismore easily curled than the plain paper, because handwriting thereon isnot easy and because the print is not excellent from the standpoint ofdurability against light. In addition, a particular one of the coatedsheets are required to be used. In the recent monochromatic ink jetrecording apparatus, the fixing property is significantly improved, andtherefore, has been put into commercial use. In the case of the colorink jet recording apparatus, however, the fixing property of the mixedcolor print portion is not good because the color mixture print isprovided by overlapping of the different color ink dots, and therefore,the quantity of the ink is twice as much as the monochromatic print forthe same picture element.

On the other hand, the recording material is a transparent sheet for anoverhead projector (OHP) which has a relatively low ink absorption rate,or plain paper having a relatively low ink absorption rate, the spreadof the ink droplet shot on the recording material is small, with theresult of a smaller dot printed. Therefore, the density of the record isrelatively low. In addition, image density difference occurs between themonochromatic print (BK, Y, M or C) and a color mixed print (R, G or B).Particularly, the black print portion looks poor as compared with theother print portion.

The conventional recording apparatus of this type has been so designedto match the coated sheet having a relatively high spread rate.Therefore, the ink droplet is too small as for the recording materialhaving the low ink absorption rate. Therefore, the density of the blackprint decreases.

Thus, when the color recording is carried out on the recording materialhaving the low ink absorption rate, a monochromatic color pictureelement has a smaller ink spread, and therefore, has a smaller areafactor with the result of the low image density.

Referring to FIG. 7, a case is shown in which black characters and colorpatterns such as graphs are printed in the black character print portionBP and a color print portion CP, respectively. The color print portionCP is generally recognized as pattern, and therefore, it is sufficientif the pattern can be recognized, even if the density is slightly low.However, as for the black character print portion BP, the charactershave to be correctly recognized, and therefore, a sufficient printdensity is desired. This has not been completely accomplished in aconventional color ink jet recording apparatus.

Since a mixture of yellow, magenta and cyan colors represents black,three colors are enough theoretically. However, the black color providedby the mixture of the three colors is not clear. For this reason, acolor recording apparatus generally uses an independent black color. Insuch a color ink jet recording apparatus, monochromatic documents areprinted using only the black (BK) ink.

Usually, in an ink jet recording apparatus, droplets of the ink isdischarged through a discharge outlet or outlets to the recordingmaterial, usually paper. Therefore, a droplet of the ink forms acircular dot on the recording material, and a character or an image isprovided by gathering of such circular ink dots. The recording iscarried out with the predetermined ink discharging frequency and with apredetermined scanning pitch. Therefore, even if the droplets aresuccessively discharged, vacancies are provided between adjacent dots onthe recording material, if they are seen microscopically. The vacanciesmay be a cause of the low image density, and particularly when adocument is recorded with black ink, it is not desirable.

Accordingly, it is a principal object of the present invention toprovide an ink jet recording method and apparatus wherein a high qualityof the images can be produced on a recording material having arelatively low ink absorption rate.

It is another object of the present invention to provide an ink jetrecording method and apparatus usable with a recording material having arelatively low ink absorption rate, and wherein the black print portionis not poor as compared with the color print portion, so that the highquality of the image is assured.

According to an aspect of,the present invention, there is provided arecording apparatus having a black ink recording head for dischargingblack ink onto a recording material and at least one single colornon-black recording head for discharging non-black ink onto therecording material, comprising: a recording head driver for driving therecording heads to discharge the ink onto the recording material; and acontroller for controlling said recording head driver so that a volume,per unit area of the recording material, of the black ink dischargedfrom the blue ink recording head and deposited on a recording region ofthe recording material is larger than that of the non-black inkdischarged from the non-black ink recording head and deposited on arecording region of the recording material.

According to another aspect of the present invention, there is provideda recording apparatus having a black ink recording head for dischargingblack ink onto a recording material and at least one single colornon-black recording head for discharging non-black ink onto therecording material, comprising: a recording head driver for driving therecording heads to discharge the ink onto the recording material; and acontroller for controlling said recording head driver to operate saidblack ink recording head through a number of recording steps which islarger than a number of recording steps by the non-black ink recordinghead.

According to a further aspect of the present invention, there isprovided a color ink jet recording apparatus, wherein each of therecording heads has plural ink discharging outlets; said recording headsare juxtaposed on a carriage; said plural recording heads dischargescyan, magenta, yellow and black ink materials while the carriage isscanningly moving along the recording material to effect color recordingon the material, comprising: head driver for driving the recording headsto discharge the associated color ink onto the recording material; and acontroller for controlling said head driver so that the number ofscanning movements of said black ink recording head is larger than thenumber of scanning movements of any one of cyan, magenta and yellow inkrecording heads for mixed color recording.

According to a yet further aspect of the present invention, there isprovided a recording apparatus, comprising: a black ink recording headfor discharging black into onto a recording material; at least onesingle color non-black recording head for discharging non-black ink ontothe recording material; a recording head driver for driving both of saidblack ink recording head and said non-black ink recording head so thatthe non-black ink is present between dots of the black ink.

According to a yet further object of the present invention, there isprovided a recording apparatus, comprising: a black ink recording headfor discharging black into onto a recording material; at least onesingle color non-black recording head for discharging non-black ink ontothe recording material; a recording head driver for driving both of saidblack ink recording head and said non-black ink recording head so thatthe non-black ink and the black ink are superposed, on the recordingmaterial.

According to a first embodiment of the present invention, a largervolume of black ink droplet is provided to the black ink recording areathan a non-black single ink recording area, by which the black recordingis sufficiently conspicuous even if the used recording material has arelatively low ink absorption rate, and therefore, a high quality printcan be provided without poor black print.

According to a second embodiment of the present invention, a black colorrecording head for discharging black ink scans the recording material aplurality of times to provide the black print. In this case one pictureelement is divided into a plurality of subordinate picture elements, andthe plural scans print different subordinate picture elements. Each ofscans of the recording heads for cyan, magenta and yellow colors for thepurpose of color mixture recording, some subordinate dots are omitted(thinning), so that even if the recording is effected to the plain paperor the like, no spread appears in the color mixture record, and theblack record is clear.

According to a third embodiment of the present invention, a black inkrecording head and another non-black ink recording head are both drivento record black dots so that a color ink dot such as cyan or magenta dotare provided between adjacent black dots, by which the black imagedensity is increased by one scanning operation, so that good contrast ofthe record can be provided.

The recording head of the recording apparatus according to the presentinvention may be in the form of a replaceable recording head which iselectrically connected with the main assembly of the recording apparatusand is supplied with ink therefrom when it is mounted in the mainassembly, or in the form of a cartridge having an integral inkcontainer.

These and other objects, features and advantages of the presentinvention will become more apparent upon a consideration of thefollowing description of the preferred embodiments of the presentinvention taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a recording apparatus according to anembodiment of the present invention.

FIG. 2 is a perspective view of the recording apparatus with an outercasing.

FIG. 3 is a block diagram of a control system for the recordingapparatus according to the present invention.

FIGS. 4A and 4B are top plan views of operational panels.

FIG. 5A illustrates dot formations in a single color print in arecording apparatus according to a first embodiment of the presentinvention.

FIG. 5B illustrates dot formations of a color mixture print portion anda black character print portion in the first embodiment.

FIG. 6 is a flow chart illustrating sequential recording operations forsetting the operational mode in the first embodiment.

FIG. 7 illustrates a black character print portion and a color printportion on a recording material.

FIGS. 8, 9 and 10 illustrate ink dot formations in a recording apparatusaccording to a second embodiment of the present invention.

FIG. 11 is a block diagram of a control system of the apparatusaccording to the third embodiment.

FIG. 12 is a block diagram of a recording system of the recordingapparatus according to the third embodiment.

FIG. 13 is a flow chart illustrating the sequential operations forsetting an operational mode in the third embodiment.

FIG. 14 is a timing chart of an example of a head driving pulse in ablack mixture recording in the recording apparatus according to thethird embodiment.

FIGS. 15 and 16 are enlarged views of the dot record provided by therecording apparatus according to the third embodiment.

FIG. 17 is a block diagram of a system when the recording apparatusaccording to the present invention is used in an information processingapparatus.

FIG. 18 shows an outer appearance of the information processingapparatus of FIG. 17.

FIG. 19 shows another example of the information processing apparatus.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The preferred embodiments of the present invention will be described indetail in conjunction with the accompanying drawings.

Referring to FIG. 1, there is shown a main assembly of a recordingapparatus according to the present invention. The main assembly 1 of therecording apparatus is loaded with a color image forming recording headunit comprising a black (BK) recording head 2A, a cyan (C) recordinghead 2B, a magenta (M) recording head 2C and a yellow (Y) recording head2D, which are arranged in a line along a scanning direction of therecording head unit. The recording head unit 2 is mounted on a carriage3 of the main assembly 1.

That surface of each of the recording heads 2A, 2B, 2C and 2D which isfaced to a recording material 7 is provided with a plurality of inkejection (discharging) outlets arranged vertically in the Figure at thepredetermined intervals. Corresponding to the ink ejection outlets,there are provided electrothermal transducers (heat generatingresistor), which is driven in accordance with the information to berecorded. The driving of the heat generating resistor produces a bubblein the ink, by which a pressure is produced enough to eject the inkdroplet to the recording material. Therefore, a pattern is provided bythe dots formed with the ejected ink droplets. Each of the recordingheads has a circuit board including heater drivers for driving theelectrothermal transducers.

A controller is formed on a control board 8 and includes a controlcircuit (CPU) for the recording apparatus, ROM and RAM or the like inconnection with the control circuit. The controller receives instructionsignals and data signals (record information) from a host apparatus 9such as computer. In response to the received signals, the controllerenergizes driving sources such as motors and applies a driving voltage(heating voltage) to the electrothermal transducers of the recordingheads 2A-2D through the heater drivers.

The carriage 3 is connected with a belt 4 and is reciprocated in adirection of an arrow C along a guide shaft 5 by an unshown motor. Aplaten 6 guides the recording material to a recording position,maintains it at the correct position, feeds the recording material andfurther to discharge the recording material in the direction of an arrowB after the recording operation. Here, the recording material may be ausual coated sheet, or a transparent film for an overhead projector(OHP).

Designated by a reference numeral 10 is an operation panel on an outercasing of the recording apparatus. It includes a switching key 10A forswitching between on-line state and off-line state, a line feed key 10B,a form feed key 10C, a recording mode switching key 10D or the like inthe setting key area. It also includes a display area including somealarming lamps, a power source lamp or another warning lamp 10E and a 7segment digit display 10H.

FIG. 2 shows an outer appearance in a perspective view of the mainassembly 1 of the recording apparatus provided with an outer casing andsupplied with a recording material in the form of a recording sheet.

When a color recording is effected on a recording, material 7, the imagedensity and the quality of the images produced on the recording material7 is different if the ink (liquid) spreading nature of the recordingmaterial 7 is different. In view of this, the apparatus of thisembodiment is operable in a mode suitable for the recording material 7such as an OHP film, which has a lower ink absorbing nature, and a modesuitable for coated paper or the like which has a high ink absorbingnature.

The selection of the modes is effected by a printer command of the hostapparatus 9 or operating a selector switch or the like on the operationpanel 10. On the basis of the selection of the mode, the ink ejecting ismade different to meet the nature of the recording material.

FIGS. 3, 4A and 4B show the structure of the circuit for performing theabove operation in the recording apparatus, and examples of switches onpanels 10 for selecting the modes described above. The circuit of FIG. 3comprises an interface 21 with the host apparatus 9, a driving system 22disposed between the driving system and the carriage 3 or the platen 6or the like, a head driving system 23 for controlling the driving ofeach of the recording heads 2A-2D through a controller 8 in accordancewith the selected mode. As shown in FIGS. 4A and 4B, the operation panelhas an on-line switch 10A, a setting switch 10G for setting in thememory of the controller 8, a mode selector switch 10D for selecting amode. The mode can be selected by a combination of operations which willbe described hereinafter. Of course, it is possible to set a commandtherefor.

When the command from the host apparatus 9 is directly used, the on-lineswitch 10A shown in FIG. 4A or 4B takes the on-position. If the panel 10actuation is used, a coated sheet mode is selected by, for example,deactuating the on-line switch 10A, actuating the setting switch 10G,and then actuating the line feed switch 10B. In the coated sheet mode,one shot is given to the single color Y, M and C dot and also for blackdot (black character). In the case of the panel shown in FIG. 4B, theon-line switch 10A is deactuated, and the mode selector switch 10D isactuated, and thereafter the setting switch 10G is actuated n-times tochange the display of the 7 segment digit display 10H when the changeddisplay is a predetermined numeral, the above-described coated sheetmode is set, and then, the mode selector switch 10D is actuated again,by which the mode is selected. This is an example. The display of themode is not limited to the numeral, but may be a character or charactersusing a display constituted by liquid crystal display having a number ofdot matrix liquid crystal segments.

When a black stressing mode is to be selected with the use of plainpaper having a low ink absorbing nature, the mode is selected in thepanel 10 of FIG. 4A, for example, by deactuating the on-line switch 10A,actuating the setting switch 10G a plurality of times, and furtheractuating the line feed switch 10B.

In the case of the panel 10 of FIG. 4B, similarly to the selecting ofthe coated sheet mode, the on-line switch 10A is deactuated, and themode selector switch 10D is actuated, and thereafter the setting switch10G is actuated m times, by which the display on the digit display 10His made the numeral representing the black stressing mode, and then, themode switch 10D is actuated again.

In the recording apparatus according to the first embodiment, when ablack character or characters or a black line or lines are to beprinted, the proper mode is selected, and the double printing iseffected in response to character codes supplied from the host apparatus9, by which the print density of the black character print portion BP isenhanced.

The ink jet recording apparatus constructed in the manner describedabove is operable in the coated paper mode and in the black stressingmode. In the coated paper mode, it provides superposing shots in theimage or characters in a mixed color, R, G or B, whereas it provides oneshot in a black character or the like, similarly to the other singlecolor (Y, M or C) images or characters. In the black stressing mode, therecording apparatus provides a color superposing or double shots, asshown in FIG. 5B in the mixed color record and in the black character,respectively, whereas it provides one shot for each picture element, asshown in FIG. 5A, in the record of monochromatic color (Y, M or C). Bydoing so, the record density can be enhanced for a black characters orletters or black frames or the like even when OHP film or anotherrecording material having a low ink absorbing nature, and therefore, ahigh quality of the image can be provided. It is preferable that thevolume of the black ink for the black character per one shot ispreferably larger than a focal volume of the ink for the mixed colorrecord per one shot. As regards the yellow, magenta and cyan colors, therecording is effected with single shot, and therefore, the ink materialsfor these colors are not wastefully consumed. The double or superposingink shots may be effected during one scan, but may be effected in twoscans.

Foregoing description of the embodiment, the ink is superposedly shot,but it is a possible alternative that the second shot may be effectedwith a deviation of a half pitch of the minimum resolution pictureelement. This can be accomplished by hardware or software.

As for the output of CAD, the density of a line image is desirably high.In this case, it is preferable to provide a CAD output mode. Then, theoperator can make selection from one dot recording and double dotsrecording for a line image recording. The CAD output mode can beselected in the similar manner as in the coated paper mode selecting ina panel 10 of FIG. 4B. The plain paper mode, the OHP film mode may beselected in the similar manner.

FIG. 6 shows the process of selecting a mode from the above-describedmodes. When the main switch is actuated, and the mode is selected by acommand from the host apparatus 9 or by the operator in the panel 10,the controller 8 discriminates as to whether or not the mode is thecoated paper mode or not, at step S1. If so, the operation proceeds tostep S2, by which the conventional routine is carried out in which oneshot is provided for cyan, magenta, yellow or black color, andsuperposing (two) shots are effected for a mixed color such as red,green and blue. If the result of discrimination at step S1 is negative,the operation proceeds to step S3, wherein the discrimination is made asto whether or not the selected mode is the plain paper mode or not.

If so, the operation proceeds to step S4 wherein the discrimination ismade as to whether or not the mode is the black stressing mode or not.If so, step S5 is executed wherein the black stressing mode operation iscarried out so that the double shots is carried out for black characteror the like. If the result of discrimination at step S4 is negative, theoperation proceeds to step S6 where the CAD outputting mode operation iscarried out so that the black double shots are provided only for theblack line images. If the result of discrimination at step S3 isnegative, the operation proceeds to step S7 in which the discriminationis further made as to whether or not the selected mode is the OHP filmmode. If not, the absence of used mode is finally discriminated, and theoperation returns to step S1. If so, the operation proceeds to step S8where the OHP film mode shooting carried out for the color print.

The driving means for the recording head is controlled by the controlmeans so that the volume of the black ink per unit area discharged fromthe black ink recording head and deposited on the recording region ofthe recording medium is larger than the volume of the single colornon-black ink discharged from the non-black recording head and depositedon the recording region of the recording material. Therefore, theresultant record is as shown in FIGS. 5A and 5B. More particularly, theaverage volume of the ink deposited on one pixel location to receive theink is controlled in the manner described above. Here, the pixellocations are points on the recording material that may be chosen aslocations where droplets of ink are to be deposited to form dots upondrying. The pixels are usually visualized as lying on the nodes of araster of regularly arranged points in two dimensions. In the foregoingdescription, the recording methods are different between the black inkrecording head and the non-black ink recording head. However, it is apossible alternative that a non-black ink recording head and a mixedcolor recording head are combined so that the volume of a single colorink per unit area discharged from the single color ink recording headand deposited on the recording region of the recording material is notless than the volume of the mixed color ink per unit area dischargedfrom the mixed color recording head and deposited on the recordingregion of the recording material as a mixed color dot. A furtheralternative is that the volume of the ink per unit area discharged fromthe recording head and deposited on the character region or a line imageregion of the recording material is larger than the volume of the inkper unit area deposited on the recording region of the recordingmaterial other than the character or line image region.

As described in the foregoing, according to the first embodiment of thepresent invention, when an OHP film or plain paper or the like which hasa low ink absorbing nature is used as the recording material, the volumeof the ink shot to the black character, letter or line image or the likeis made larger than the volume of the shot non-black ink, by which thenon-black print regions have suppressed ink to permit easy patternrecognition, whereas the characters or the like have high image densityto permit better reading. As a result, the print quality can be enhancedcorresponding to the natures of the recording materials.

What is important in the color recording on plain paper is, in the caseof the record image as shown in FIG. 7, for example, that the blackcharacter print BP and the black frames are sharp and clear, whereas theother color print portion CP is only required to be clear in the colorrecognition. If they are satisfied, sufficiently high quality documentsmay be provided.

However, as described hereinbefore, in the color mixed portions such asred, green and blue portions, the volume of the shot ink is 200% due tothe superposition of the different color shots. In this case, the plainpaper is not capable of sufficiently quickly absorb the ink. Thisapplies to the case wherein the plural shots are given for the purposeof enhancing black. Then, the record is unsharp or the print surface iscontaminated.

The second embodiment of the present invention which will be describedhereinafter, is particularly directed so this problem. Summary, thisembodiment is such that for the print portion of black characters or thelike, the dots are printed for all of the picture elements (unit dot)constituting a datum on the basis of dot data in order to advantageouslyusing the fine line recording capability provided by the precision inkejection outlets of the recording apparatus, whereas for red, green,blue and mixed color print portions, only partial dot or dots areprinted so as to promote ink absorption provided adjacent to the partialprinted dots.

FIG. 8 shows the printed dots in the second embodiment of the presentinvention. In this example, a unit datum is divided into or converted toa plurality of picture elements (2×2), and the recording is effected onthe basis of the data. The broken line and solid line circles representthe regions where the data are to present. The solid line circlerepresents the dot actually shot by the ink in this example. By a firstscan by the recording heads 2A-2D, black, yellow, magenta and cyan inkdots are shot at a pair of diagonally opposite positions of the dividedpicture elements. For the mixed colors, red, green and blue, they areprovided by superposition of yellow, magenta and cyan, and therefore,the superposing shots are given to the same positions during the firstscan. However, the other pair of diagonally opposite positions includingthe broken line circles are free from shot dot, and therefore, remain asspaces functioning to absorb the ink. Therefore, the ink is easilyfixed.

In the second scan, as shown in FIG. 8B, only black ink dots are shot atthe opposite diagonal positions. Therefore, in the black print portions,the dots are shot for all of the picture elements constituting the datumas a solid dot. Thus, the black print can be made conspicuous. Inaddition, in this example, the black ink shot during the first scan isabsorbed until the second scan, so that the black record is fixedbetter. Furthermore, the density of the mixed color record (R, G or B)is sufficiently high with the stabilized fixing property. In the secondscan, only the black ink dots may be shot superposedly to the samepositions as in FIG. 8A. Even in this case, the ink absorbing spaces areprovided at the other diagonal positions, so that the fixing property isimproved with the enhanced black record.

FIG. 9 shows an example wherein a unit datum is divided into orconverted to 3×3 picture elements. In this example, the first scanshoots the ink dots to the divided dots of solid lines for black,yellow, magenta and cyan colors, as shown in FIG. 9A. In the secondscan, only black ink is shot to the divided picture elements of brokenlines. According to this example, the black color can be stressed, andthe ink absorbing spaces are provided for the red, green and blue dotsto be provided by superposing yellow, magenta and cyan colors, andtherefore, the image fixing property can be improved.

FIG. 10 shows a further example of recording dots. In this example, onedot pattern datum for the respective ink materials is determined for theplain paper mode selected. A datum is converted and is formed as n×n(2×2 in this example) picture elements are provided in the form of amatrix. The 100% shooting is effected for each of the colors relative tothe minimum resolution of the recording head, and still, the recordfixing property is improved.

In this embodiment, the color recording is effected with the pictureelement density of 180 dpi, while the minimum resolution is 360 dpi. Inthe first scan, as shown in FIG. 10A, the ink dots are shot at one ofthe diagonal positions for a single color (Y, M, C or BK) record. As forthe color mixed record (R, G or B), the colors are superposed on thebasis of the divided dot data for yellow, magenta and cyan. The secondscan shoots the ink dots at the other diagonal positions for black,yellow, magenta and cyan. The ink is absorbed by the recording materialafter the completion of the first scan and before the start of thesecond scan. Therefore, the ink is fixed in good order for the black,yellow, magenta and cyan colors. As for the color mixed dots (red, greenor blue) provided by the mixture of the yellow, magenta and cyan color,the ink is absorbed by the spaces therearound, and therefore, the ink isfixed again in good order. The conversion of the binary datum to the 2×2matrix may be made using gage array LSI (GA) or the like of thecontroller.

In the foregoing description, the number of scans for the black colorrecord by the black ink recording head is larger than the number ofscans for the mixed color recording by the cyan, magenta or yellow inkrecording head. However, this is not limiting and it is a possiblealternative that the number of scans for a single color recording by thesingle color recording head is larger than the number of scans for themixed color recording by a mixed color recording head for ejecting eachof color ink other than the single colors. It is a further alternativethat the number of scans for the character or line image recording islarger than the number of scans for the recording other than thecharacters or the line images.

As described in the foregoing, according to the second embodiment, thenumber of scans for the black recording is larger than the number ofscans for the mixed color recording, by which the black color is madeconspicuous, and in addition, the ink dots are formed at differentpositions in the scans, so that the ink is more easily fixed. In thecolor record portion other than the black record portion, the patternthereof can be sufficiently recognized. Where the recording is effectedwith yellow, magenta, cyan and black recording heads, the blackrecording head scans continuously, and therefore, the two scans can becarried out one reciprocation, by which the throughput is better.

FIG. 11 shows a third embodiment which is also directed to an ink jetrecording apparatus for effecting color recording using plural color inkmaterials. A black ink recording head A ejects or discharges black inkthrough its ejection outlet to the recording material. The recordingapparatus comprises color ink recording head for ejecting non-black inkthrough its ejection outlet. Control means C drives both of the blackcolor recording head A and the non-black color recording head B so thatthe non-black or chromatic color ink is shot between black dots. In thisembodiment, the non-black ink is either of cyan and magenta inkmaterials. The control means C controls the ejection timing so that thenon-black ink is shot between adjacent black dots by deviating theejection timing by approximately ½ dot, for example. The control means Cmay controls the ejection timing so that the non-black ink is shotsuperposedly on the black dot. In addition, the control means C mayprovide a smaller amount of non-black ink than the black dot.

FIG. 12 is a block diagram of a control system of the recordingapparatus according to a third embodiment of the present invention. InFIG. 12, the central processing unit (CPU) 21 in the form of amicroprocessor is connected with a host apparatus 14 such as a computerthrough an interface 22. It controls the recording operation inaccordance with command read from the host apparatus 14 into data memory23, record information signal and in accordance with the program ordata, as shown in FIG. 13, stored in program memory 24 in the form of aROM or working memory 25 or the like.

A sheet sensor 30 detects whether or not the recording material 1 ispresent in the recording apparatus, and the detection signal is suppliedto the CPU 21 through an input port 31.

The outputs from the operation keys 10A-10D or the like on the operationpanel 10 having the same structures as described with the foregoingembodiments, are supplied to the CPU 21 through the input port 32. To analarming lamp or power source lamp 16 or the like, control signals aresupplied through an output port 36.

Dip switches 33 are provided at the bottom of the outer casing, and theoutputs thereof are transmitted to the CPU 21 through an input port 34.

Power source circuit 28 produces a logic drive voltage Vcc (5 V) fordriving control logic circuits, various motor driving voltage VM (30 V),a heater voltage (head voltage) VH (25 V) for heating the dot formingelements (electrothermal transducers) of each of the recording heads,and a back-up voltage VDDH or the like for protecting the recordingheads 2A-2D. The heating voltage VH is directly supplied to therecording heads 2A-2D, and the back-up voltage VDDH is supplied to ahead control circuit 29 and the recording head 2A-2D.

Referring to FIGS. 13, 14, 15 and 16, an example of operations of thecolor ink jet recording apparatus according to this embodiment will bedescribed. FIG. 13 is a flow chart illustrating an example of the recordprocessing step; FIG. 14 is an example of a timing chart of head drivingpulses during a black mixture recording operation which will bedescribed hereinafter; and FIGS. 15 and 16 illustrates the record on arecording material in an enlarged scale.

As shown in FIG. 13, a recording mode is selected at step S1 from acolor mode, a normal black printing mode and a normal printing mode. Theselection of the recording mode may be accomplished in the same manneras in the first embodiment, more particularly, using the panel 10 asshown in FIG. 4B, for example to select the coated sheet mode.Otherwise, the selection may be made on the basis of a command from thehost apparatus 14.

Thereafter, the discrimination is made as to whether the recording modeor the color mode is selected, at step S2. If it is not the color mode,that is, if black and white mode is selected, the discrimination isfurther made as to whether or not the normal black printing mode isselected, at step S3. If it is the normal black printing mode, the usualblack and white recording is carried out using only the black ink (BK),similarly to the conventional recording machines. If it is not thenormal black printing mode, the black mix recording process according tothis embodiment is carried out, at step S4.

In the black mix recording, as shown in FIG. 14, for example, not onlythe black ink but also the cyan ink or magenta ink is used. In theexample of FIG. 14, the cyan or magenta ink recording head 2B or 2C issupplied with a driving pulse having the same waveform as the blackrecording but at the timing deviated by ½ dot (½ pulse) from the blackink ejection timing. The deviation of the ejection timing may beaccomplished by the software delay using proper buffer memory or counteror the like.

Therefore, the record provided by this process is, as shown in FIG. 15,cyan or magenta ink droplet (broken line) is shot at a position ½ dotdeviated from the black ink droplet (solid lines). Therefore, as shownin FIG. 15, (6), the small spaces (white) between adjacent black inkdots are filled with cyan or magenta ink droplets, substantiallycompletely, so that the spaces disappear. With this aid of the spread ofthe ink, the space is considered to be completely removed. By this, therecording density is improved, so that the high quality recording can beprovided which is not provided by the usual recording. This process canbe completed by a single recording scanning operation, and therefore,the high speed recording as in the usual recording mode is accomplished.The spaces have a size which is relatively smaller as compared with thesize of the ink dots, and in addition, black ink is superposed withanother color ink, and therefore, the change of the color attributableto the use of the cyan or magenta ink is not practically seen.Considering fact that black ink which is slightly blue of widely usedwith fountain pens or printing, the above-described mixed black color ispractically of no problem. As will be understood from the foregoing,according to this embodiment, the cyan or magenta ink droplets are shotnot to the space resulting between adjacent black dots from improperblack ink recording head ejection or the like, but to the spaces betweenadjacent black dots which are necessarily provided by correct ejectionoperations of the black ink recording head. By doing so, the spaces areremoved to improve the record density. In the case of the recordingapparatus wherein the cyan or magenta ink shots proceeds the black inkshots, the cyan or magenta shots may be carried out at the properpositions before the black droplets are shot. In the examples of FIGS.14 and 15, one cyan or magenta dot is provided for one black dot. It isa possible alternatively that one cyan or magenta dot is provided fortwo black dots, for example, thus a smaller number of non-black dots areprovided than the number of black dots. By the reduction of the numberof non-black dots, the resultant color is closer to the pure black. Thisreduced shot can be accomplished by, for example, skipping the readingof the recording data from the buffer every other dots for the non-blackshots. This is advantageous when the sharpness of the image isparticularly desired or when the recording paper is the plain paperhaving a major of easier ink spread.

As shown in FIG. 16, the cyan or magenta ink may be ejected in thematched timing with the black ink ejection. By doing so, the density ofthe black recording can be improved. By the shot of the cyan or magentaink substantially on the black dot, as shown in FIG. 16A, the inkdroplets are mixed, as shown in FIG. 16B, and the mixture spread towardthe adjacent black dots, so that the small spaces are disappears. Inthis case, one cyan or magenta dot is shot for two black dots.

The black mixture recording is effective also in the color mode.Referring back to FIG. 13, if the color mode is discriminated at stepS2, and if the normal recording is discriminated at step S5, theconventional color recording is executed. If it is not the normalrecording, the black mixture recording process is carried out at stepS6, wherein the black color is stressed. The black mixture recordingprocess is similar to the black mixture recording process at step S4described hereinbefore. In addition to the normal color recordingoperation, the black mixture recording operation described with the stepS4 is executed. For example, if the cyan color ink is used for the blackmixture recording, the cyan ink dot is used both for the color imageproduction and for the black stressing. This can be accomplished byusing a driving signal which is a combination of a cyan drive signal forthe normal color recording and a cyan signal for the black stressing, asshown in FIG. 14. As will be understood, the black mixture recordingprocess in the color mode is effective to increase the density of theblack record, and therefore, the black line or black frames are stressedto provide clear and high contrast color image. This is particularlypreferable in the case where a color picture and sentences are mixed onone and the same page.

In the foregoing description, the black ink recording head and achromatic color ink recording head are both driven to shoot thechromatic color ink at the position between adjacent black dots, or thechromatic color ink is shot one of the adjacent black dots. However, itis a possible alternative that a first color ink recording head and asecond color ink recording head are both driven to shoot the secondcolor ink between the first color ink dots, or that the second color inkis shot at the position superposing one of adjacent first color inkdots. It is a further alternative that the deposition of the secondcolor ink is effected only character or the like record or to a lineimage.

As described in the foregoing, according to the third embodiment of thepresent invention, the black ink recording head and the non-black inkrecording head are driven to shoot the non-black ink between black dots,and therefore, the black record density is enhanced by one recordingscan without decreasing the ejection frequency and without decreasingthe recording speed. Therefore, the print quality is improved.

The present invention is particularly suitably usable in an ink jetrecording head and recording apparatus wherein thermal energy by anelectrothermal transducer, laser beam or the like is used to cause achange of state of the ink to eject or discharge the ink. This isbecause the high density of the picture elements and the high resolutionof the recording are possible.

The typical structure and the operational principle are preferably theones disclosed in U.S. Pat. Nos. 4,723,129 and 4,740,796. The principleand structure are applicable to a so-called on-demand type recordingsystem and a continuous type recording system. Particularly, however, itis suitable for the on-demand type because the principle is such that atleast one driving signal is applied to an electrothermal transducerdisposed on a liquid (ink) retaining sheet or liquid passage, thedriving signal being enough to provide such a quick temperature risebeyond a departure from nucleation boiling point, by which the thermalenergy is provided by the electrothermal transducer to produce filmboiling on the heating portion of the recording head, whereby a bubblecan be formed in the liquid (ink) corresponding to each of the drivingsignals. By the production, development and contraction of the bubble,the liquid (ink) is ejected through an ejection outlet to produce atleast one droplet. The driving signal is preferably in the form of apulse, because the development and contraction of the bubble can beeffected instantaneously, and therefore, the liquid (ink) is ejectedwith quick response. The driving signal in the form of the pulse ispreferably such as disclosed in U.S. Pat. No. 4,463,359 and 4,345,262.In addition, the temperature increasing rate of the heating surface ispreferably such as disclosed in U.S. Pat. No. 4,313,124.

The structure of the recording head may be as shown in U.S. Pat. Nos.4,558,333 and 4,459,600 wherein the heating portion is disposed at abent portion, as well as the structure of the combination of theejection outlet, liquid passage and the electrothermal transducer asdisclosed in the above-mentioned patents. In addition, the presentinvention is applicable to the structure disclosed in Japanese Laid-OpenPatent Application No. 123670/1984 wherein a common slit is used as theejection outlet for plural electrothermal transducers, and to thestructure disclosed in Japanese Laid-Open Patent Application No.138461/1984 wherein an opening for absorbing pressure wave of thethermal energy is formed corresponding to the ejecting portion. This isbecause the present invention is effective to perform the recordingoperation with certainty and at high efficiency irrespective of the typeof the recording head.

The present invention is effectively applicable to a so-called full-linetype recording head having a length corresponding to the maximumrecording width. Such a recording head may comprise a single recordinghead and plural recording head combined to cover the maximum width.

In addition, the present invention is applicable to a serial typerecording head wherein the recording head is fixed on the main assembly,to a replaceable chip type recording head which is connectedelectrically with the main apparatus and can be supplied with the inkwhen it is mounted in the main assembly, or to a cartridge typerecording head having an integral ink container.

The provisions of the recovery means and/or the auxiliary means for thepreliminary operation are preferable, because they can further stabilizethe effects of the present invention. As for such means, there are knowncapping means for the recording head, cleaning means therefor, pressingor sucking means, preliminary heating means which may be theelectrothermal transducer, an additional heating element or acombination thereof. Also, means for effecting preliminary ejection (notfor the recording operation) can stabilize the recording operation.

As regards the variation of the recording heads mountable, it may be asingle corresponding to a single color ink, or may be pluralcorresponding to the plurality of ink materials having differentrecording color or density. The present invention is effectivelyapplicable to an apparatus having at least one of a monochromatic modemainly with black, a multi-color mode with different color ink materialsand/or a full-color mode using the mixture of the colors, which may bean integrally formed recording unit or a combination of plural recordingheads.

Furthermore, in the foregoing embodiment, the ink has been liquid. Itmay be, however, an ink material which is solidified below the roomtemperature but liquefied at the room temperature. Since the ink iscontrolled within the temperature not lower than 30° C. and not higherthan 70° C. to stabilize the viscosity of the ink to provide thestabilized ejection in usual recording apparatus of this type, the inkmay be such that it is liquid within the temperature range when therecording signal is the present invention is applicable to other typesof ink. In one of them, the temperature rise due to the thermal energyis positively prevented by consuming it for the state change of the inkfrom the solid state to the liquid state. Another ink material issolidified when it is left, to prevent the evaporation of the ink. Ineither of the cases, the application of the recording signal producingthermal energy, the ink is liquefied, and the liquefied ink may, beejected. Another ink material may start to be solidified at the timewhen it reaches the recording material. The present invention is alsoapplicable to such an ink material as is liquefied by the application ofthe thermal energy. Such an ink material may be retained as a liquid orsolid material in through holes or recesses formed in a porous sheet asdisclosed in Japanese Laid-Open Patent Application No. 56847/1979 andJapanese Laid-Open Patent Application No. 71260/1985. The sheet is facedto the electrothermal transducers. The most effective one for the inkmaterials described above is the film boiling system.

The ink jet recording apparatus may be used as an output terminal of aninformation processing apparatus such as computer or the like, as acopying apparatus combined with an image reader or the like, or as afacsimile machine having information sending and receiving functions.

FIG. 17 is a block diagram of a system of the recording apparatus ofthis invention wherein it is applied to an information processingapparatus having a function of a wordprocessor, a personal computer,facsimile machine and copying machine.

A controller 201 controls the entirety of the apparatus and is providedwith CPU in the form of a microprocessor or the like and various I/Oports to supply control signals, data signals and the like to variousparts and to receive control signals and data signals from variousparts. A display 202 displays various menu, document information andimage data read by an image reader 207, or the like. A touch panel 203is of a pressure sensitive type of a transparent material mounted on thedisplay 202. By depressing by fingers or the like the surface thereof,the items or coordinate positions may be input on the display 202.

An FM (frequency modulation) sound source 204 stores music informationproduced by music editor or the like is stored in a memory 210 or anexternal memory 212 as digital data. They are read out from the memoryand is subjected to the FM modulation. The electric signals from the FMsound source 204 is converted to sensible sounds by a speaker 205. Aprinter 206 functions as an output terminal of the wordprocessorfunction, the personal computer function, the facsimile function and thecopying function. The present invention is applied to the printer 206.

An image reader 207 photo electrically reads an original and is disposedin a path of the original to read various originals for the facsimilefunction or for the copying function. Facsimile sender and receiver 208functions to send the original data read by the image reader 207 and toreceive the facsimile signals, and functions as a interface with theexternal. A telephone 209 has the usual telephone function and themessage taking function.

Memory 210 comprises a ROM for storing a system program, a managingprogram, other application programs or the like, a character font,dictionaries or the like, it stores the application program loaded froman external memory 212. It comprises also a video RAM or the like. Akeyboard 211 is used for inputting document information or variouscommands or the like. The external memory 212 is in the form of a floppydisk or a hard disk. In the external memory 212, document information,music, sound information, user's application program or the like arestored. FIGS. 18 is an external view of the information processingapparatus of FIG. 17. A flat panel display 301 is of liquid crystal typeand displays various menu and Figure and document information. On thedisplay panel 301, there is a touch panel 203. By depressing the surfaceof the touch panel 203 by a finger or the like, the items or coordinatesmay be inputted. A hand set 302 is used when the apparatus functions atelephone set. The keyboard 303 is detachably connected with the mainassembly through a cable, so that various document information andvarious data can be inputted. The keyboard 303 has various functionskeys 304 or the like. The external memory device 212 has an opening 305for permitting insertion of a floppy disk.

An original supporting platen 307 supports an original to be read by theimage reader. The original is discharged to the backside of theapparatus after being read. Upon the facsimile reception or the like,the information is recorded by an ink jet printer 307. The display 202may be in the form of CRT. However, a ferroelectric liquid crystaldisplay flat panel is desirable, because the size, thickness and theweight may be reduced.

When the information processing apparatus is used as the personalcomputer or the wordprocessor, the various information inputted on thekeyboard 211 is processed by the controller 201 in accordance with apredetermined program, and is outputted as a print by the printer 206.

When it functions as a facsimile machine, the facsimile informationsupplied from the facsimile sender and receiver 208 through thecommunication line is processed by the controller 201 in accordance withthe predetermined program, and is outputted at the printer 206.

When the apparatus function as the copying machine, the original is readby the image reader 207, and the read data is outputted as the copythrough the controller 201 at the printer 206. When it functions as asender of the facsimile machine, the original data read by the imagereader 207 is sent by the controller 201 in accordance with thepredetermined program, and thereafter, is supplied to the communicationline through the facsimile receiver 208.

The information processing apparatus described in the foregoing, may beintegral with the main assembly of the ink jet printer, as shown in FIG.19. In this case, it can be carried around with less difficulty. In thisFigure, the same reference numerals as in FIG. 18 are assigned to theelements having the corresponding functions.

When the recording apparatus of the present invention is applied to themulti-function image processing apparatus, the high-quality record canbe accomplished, and therefore, the functions of the informationprocessing can be further improved.

While the invention has been described with reference to the structuresdisclosed herein, it is not confined to the details set forth and thisapplication is intended to cover such modifications or changes as maycome within the purposes of the improvements or the scope of thefollowing claims.

What is claimed is:
 1. A recording apparatus having a black inkrecording head for discharging black ink onto a recording material andat least one single color non-black recording head for dischargingnon-black ink onto the recording material, comprising: scanning meansfor scanning said recording material with said black ink recording headand said non-black ink recording head; a recording head driver fordriving the recording heads to discharge the ink onto the recordingmaterial; and a controller for controlling said recording head driver tooperate said black ink recording head through a number of recordingsteps which is larger than a number of recording steps by the non-blackink recording head, wherein said controller causes a predetermined areaon the recording material to be scanned a plurality of times with saidblack ink recording head to provide a density higher than that providedby a single scan of said black ink recording head.
 2. An apparatusaccording to claim 1, wherein said black ink recording head in one ofsaid recording steps effects its recording in a part of a recordingregion to be recorded by said black ink recording head, and in anotherrecording step, it effects its recording in the rest of the recordingregion.
 3. An apparatus according to claim 1, wherein said recordinghead discharges the ink by thermal energy and is provided with anelectrothermal transducer for producing the thermal energy to be appliedto the ink.
 4. An apparatus according to claim 3, wherein said recordinghead discharges the ink through a discharging outlet using a pressurechange which is produced by development and contraction of a bubblewhich is produced by the thermal energy applied by the electrothermaltransducer.
 5. A copying machine having said recording apparatusaccording to any one of claims 1-4.
 6. A facsimile machine comprisingsaid recording apparatus according to any one of claims 1-4.
 7. Awordprocessor comprising a recording apparatus according to any one ofclaims 1-4.
 8. A computer comprising a recording apparatus according toany one of claims 1-4.
 9. A recording apparatus having a single colorrecording head and a mixed color recording head for ejecting ink to beused for color mixing onto a recording material, comprising: scanningmeans for scanning the recording material with said single colorrecording head and said mixed color recording head; a recording headdriver for driving the recording heads to eject the ink to the recordingmaterial; and a controller for effecting a number of recording steps bysaid single color recording head which is larger than a number ofrecording steps by said mixed color recording head, wherein saidcontroller causes a predetermined area on the recording material to bescanned a plurality of times with said single color recording head toprovide a density higher than that provided by a single scan of saidsingle color recording head.
 10. An apparatus according to claim 9,wherein said recording head discharges the ink by thermal energy and isprovided with an electrothermal transducer for producing the thermalenergy to be applied to the ink.
 11. An apparatus according to claim 10,wherein said recording head discharges the ink through a dischargingoutlet using a pressure change which is produced by development andcontraction of a bubble which is produced by the thermal energy appliedby the electrothermal transducer.
 12. A recording apparatus having arecording head for discharging ink onto a recording material,comprising: scanning means for scanning said recording material withsaid recording head; a head driver for driving said recording head toeject the ink to the recording material; and a controller forcontrolling said recording head driver for effecting a number ofrecording steps by said recording head for a character or a line imagerecording, wherein the number is larger than a number of recording stepsby said recording head for other than character and line image, whereinsaid controller causes, for recording of the character of line, therecording material to be scanned a plurality of times with saidrecording head to provide a density higher than that provided by asingle scan of said recording head.
 13. An apparatus according to claim12, wherein said recording head discharges the ink by thermal energy andis provided with an electrothermal transducer for producing the thermalenergy to be applied to the ink.
 14. An apparatus according to claim 13,wherein said recording head discharges the ink through a dischargingoutlet using a pressure change which is produced by development andcontraction of a bubble which is produced by the thermal energy appliedby the electrothermal transducer.
 15. A color ink jet recordingapparatus, having a plurality of recording heads, wherein each of therecording heads has plural ink discharging outlets; said recording headsare juxtaposed on a carriage; said plural recording heads dischargescyan, magenta, yellow and black ink materials while the carriage isscanningly moving along the recording material to effect color recordingon the material, comprising: scanning means for scanning said recordingmaterial with said recording heads; head driver for driving therecording heads to discharge the associated color ink onto the recordingmaterial; and a controller for controlling said head driver so that thenumber of scanning movements of said black ink recording head is largerthan the number of scanning movements of any one of cyan, magenta andyellow ink recording heads for mixed color recording, wherein saidcontroller causes a predetermined area on the recording material to bescanned a plurality of times with said black ink recording head toprovide a density higher than that provided by a single scan of saidblack ink recording head.
 16. An apparatus according to claim 15,wherein said recording head scans one time for a mixed color recording,and said recording head scans a plurality of times for black colorrecording.
 17. An apparatus according to claim 15, wherein saidrecording head for each of cyan, magenta and yellow ink scans aplurality of times for a single color recording, and wherein the ink isejected at different positions during different scans.
 18. An apparatusaccording to claim 15, wherein the mixed color recording is effected bysuperposition of cyan, magenta and yellow ink ejections by one scan soas to provide spaces for ink absorption between ink dots provided by thesuperposition.
 19. An apparatus according to claim 15, wherein saidrecording head discharges the ink by thermal energy and is provided withan electrothermal transducer for producing the thermal energy to beapplied to the ink.
 20. An apparatus according to claim 19, wherein saidrecording head discharges the ink through a discharging outlet using apressure change which is produced by development and contraction of abubble which is produced by the thermal energy applied by theelectrothermal transducer.
 21. A copying machine having said recordingapparatus according to any one of claims 15-20.
 22. A facsimile machinecomprising said recording apparatus according to any one of claims15-20.
 23. A wordprocessor comprising a recording apparatus according toany one of claims 15-20.
 24. A computer comprising a recording apparatusaccording to any one of claims 15-20.
 25. A color ink jet recordingapparatus, wherein each of the recording heads has plural inkdischarging outlets; said recording heads are juxtaposed on a carriage;said plural recording heads discharges ink materials while the carriageis scanningly moving along the recording material to effect colorrecording on the recording material, comprising: a head driver fordriving the recording head to discharge the associated color ink ontothe recording material; and a controller for controlling head driver sothat the number of scanning movements of a single color ink recordinghead is larger than the number of scanning movements of a mixed colorrecording head for mixed color recording, wherein said controller causesa predetermined area on the recording material to be scanned a pluralityof times with said recording head to provide a density higher than thatprovided by a single scan of said recording head.
 26. An apparatusaccording to claim 25, wherein said recording head discharges the ink bythermal energy and is provided with an electrothermal transducer forproducing the thermal energy to be applied to the ink.
 27. An apparatusaccording to claim 26, wherein said recording head discharges the inkthrough a discharging outlet using a pressure change which is producedby development and contraction of a bubble which is produced by thethermal energy applied by the electrothermal transducer.
 28. A color inkjet recording apparatus including a plurality of recording heads,wherein each of the recording heads has plural ink discharging outlets;said recording heads are juxtaposed on a carriage; said plural recordingheads discharges ink materials while the carriage is scanningly movingalong the recording material to effect recording on the recordingmaterial, comprising: a head driver for driving the recording heads todischarge the ink; and a controller for controlling said head driver sothat the number of scanning movements of said recording head for acharacter or line image is larger than the number of scanning movementsfor other than the character or line images, wherein said controllercauses a predetermined area on the recording material to be scanned aplurality of times with said recording head to provide a density higherthan that provided by a single scan of said recording head.
 29. Anapparatus according to claim 28, wherein said recording head dischargesthe ink by thermal energy and is provided with an electrothermaltransducer for producing the thermal energy to be applied to the ink.30. An apparatus according to claim 29, wherein said recording headdischarges the ink through a discharging outlet using a pressure changewhich is produced by development and contraction of a bubble which isproduced by the thermal energy applied by the electrothermal transducer.31. A recording apparatus, comprising: a black ink recording head fordischarging black onto a recording material; at least one single colornon-black recording head for discharging non-black ink onto therecording material; a recording head driver for driving both of saidblack ink recording head and said non-black ink recording head inaccordance with image data, wherein said recording head driver drivessaid black ink recording head to record dots for an area of a blackimage indicated by the image data and to eject the non-black ink betweendots of the black ink.
 32. An apparatus according to claim 31, whereinthe non-black ink is at least one of cyan or magenta ink.
 33. Anapparatus according to claim 31, wherein said driver drives saidnon-black ink recording head such that a dot of the non-black ink isprinted at a position separated from a dot of the black ink bysubstantially ½ dot.
 34. An apparatus according to claim 31, wherein anumber of the non-black ink dots is smaller than that of the black inkdots.
 35. An apparatus according to claim 31, wherein said recordinghead discharges the ink by thermal energy and is provided with anelectrothermal transducer for producing the thermal energy to be appliedto the ink.
 36. An apparatus according to claim 35, wherein saidrecording head discharges the ink through an ejection outlet using apressure change which is produced by development and contraction of abubble which is produced by the thermal energy applied by theelectrothermal transducer.
 37. A copying machine having said recordingapparatus according to any one of claims 31-36.
 38. A facsimile machinecomprising said recording apparatus according to any one of claims31-36.
 39. A wordprocessor comprising a recording apparatus according toany one of claims 32-36.
 40. A computer comprising a recording apparatusaccording to any one of claims 31-36.
 41. A recording apparatus,comprising: a black ink recording head for discharging black onto arecording material; at least one single color non-black recording headfor discharging non-black ink onto the recording material; a recordinghead driver for driving both of said black ink recording head and saidnon-black ink recording head in accordance with image data, wherein saidrecording head driver drives said black ink recording head and saidnon-black ink recording head to record dots for an area of a black imageindicated by the image data so that the non-black ink and the black inkare superposed.
 42. An apparatus according to claim 41, wherein thenon-black ink is at least one of cyan or magenta ink.
 43. A recordingapparatus, comprising: a first color ink recording head for dischargingfirst color ink to a recording material; at least one second color inkrecording head for discharging second color ink having a color differentfrom that of the first color ink; and a head driver for driving both ofsaid first color ink and second color ink recording heads in accordancewith image data, wherein said recording head driver drives said firstcolor ink recording head to record dots for an area of a first colorimage indicated by the image data and to elect the second color inkbetween dots of the black ink.
 44. An apparatus according to claim 43,wherein said recording head discharges the ink by thermal energy and isprovided with an electrothermal transducer for producing the thermalenergy to be applied to the ink.
 45. An apparatus according to claim 44,wherein said recording head discharges the ink through a dischargingoutlet using a pressure change which is produced by development andcontraction of a bubble which is produced by the thermal energy appliedby the electrothermal transducer.
 46. An apparatus according to claim43, wherein said head driver drives both of the recording heads so thatthe second color ink is present between the dots of the first color ink,for recording character or line image.
 47. A recording apparatus,comprising: a first color ink recording head for discharging first colorink to a recording material; at least one second color ink recordinghead for discharging second color ink having a color different from thatof the first color ink; and a head driver for driving both of said firstcolor ink and second color ink recording heads in accordance with imagedata, wherein said recording head driver drives said first color inkrecording head to record dots for an area of a first color imageindicated by the image data and to eject the second color ink betweendots of the black ink.
 48. An apparatus according to claim 47, whereinsaid recording head discharges the ink by thermal energy and is providedwith an electrothermal transducer for producing the thermal energy to beapplied to the ink.
 49. An apparatus according to claim 48, wherein saidrecording head discharges the ink through a discharging outlet using apressure change which is produced by development and contraction of abubble which is produced by the thermal energy applied by theelectrothermal transducer.
 50. An apparatus according to claim 47,wherein said head driver drives both of the recording heads so that thesecond color ink is present between the dots of the first color ink, forrecording character or line image.